Whey CR effects

[Guest guest]

Hi All,

It seems to be from the not pdf-available below paper that " the branched chain

amino

acid (BCAA) content of whey appears to contribute significantly to preservation

of

lean mass during energy restriction and expansion of lean mass in the absence of

energy restriction " .

Background - Thermodynamics and energy balance are clearly core factors involved

in

the obesity epidemic, with small increases in energy intake coupled with

declining

physical activity resulting in net positive energy balance and progressive

weight

and fat gain. Consequently, the obesity epidemic is often reduced to a simple

question of energy balance, and proposed strategies accordingly focus upon best

approaches to induce negative energy balance. However, obesity is a complex

genetic

trait, with multiple genes interacting to confer relative resistance or

susceptibility to positive energy balance. Similarly, dietary components and

patterns may affect the same metabolic pathways affected by genetic

susceptibility

and thereby alter energy portioning and obesity risk. A growing body of

evidence,

discussed in this review, suggests that dairy whey contains compounds that exert

such effects and thereby contribute to healthy weight management.

Review - We have found dairy-rich diets to attenuate body fat accumulation and

weigh

gain during periods of over-consumption of an energy dense diet and to increase

fat

breakdown and oxidation while preserving lean tissue during energy restriction.

The

underlying theory is that the calcitriol released in response to sub-optimal

calcium

intakes stimulates lipogenic gene expression and lipogenesis and inhibits

lipolysis

and fat oxidation, resulting in increased adipocyte triglyceride storage and

excess

adiposity, while the higher levels of calcium contained in dairy suppress

calcitriol

and exert the opposite effect. In addition, calcitriol inhibits adipocyte

mitochondrial uncoupling and apoptosis, resulting in increased efficiency of

energy

storage on low calcium diets, while greater adipocyte uncoupling, energy

dissipation

and apoptosis occurs on dairy-rich diets. While these effects are attributable,

in

part, to calcium suppression of calcitriol, dairy is more than twice as

effective as

calcium per se in inhibiting adiposity, and this additional bioactivity resides

in

the whey fraction. Moreover, calcium is without effect on preserving lean mass

during energy restriction, while whey confers significant protection. The

angiotensin converting enzyme (ACE) inhibitory activity of whey contains a

portion

of this additional activity, as it attenuates autocrine angiotensin II-induced

adipocyte lipogenesis. However, combining calcium and whey-derived ACE

inhibitors

produces an effect that is significantly less potent than that of intact whey,

indicating the presence of other anti-obesity factors in whey; the identity of

these

factors is presently under investigation. Moreover, this combination does not

retain

the ability of intact whey to protect lean mass. Instead, the branched chain

amino

acid (BCAA) content of whey appears to contribute significantly to preservation

of

lean mass during energy restriction and expansion of lean mass in the absence of

energy restriction; this effect is likely due to leucine stimulation of muscle

protein synthesis and may also contribute to reduced adiposity as a result of

the

additional energetic cost of muscle protein synthesis. However, whey-free diets

containing BCAA confer less lean mass protection than intact whey.

Conclusions - Whey components have the potential to play a significant role in

weight management and protection of lean mass during dieting. While the calcium

content of whey accounts for a portion of this effect (<50%), there are clearly

other bioactive whey components which also contribute. However, although both

ACE-inhibitory peptides and BCAA contribute to this additional bioactivity, they

cannot fully account for the anti-obesity and muscle-protective properties of

whey,

indicating that there are other, as of yet unidentified, whey components which

contribute to these effects.

Al Pater, PhD; email: old542000@...

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